ux0:/data/retroarch/system/bios_CD_U.bin
Place files directly in the system folder. Do not put them in subfolders unless a specific core (like Dreamcast) requires it. Essential BIOS Files List bios files for retroarch ps vita link
For RetroArch on the PS Vita, BIOS files are the original console firmware required to run certain systems (like PS1, Sega CD, and GBA) with high accuracy 📁 BIOS Directory Location The standard directory for BIOS files on the PS Vita is: ux0:data/retroarch/system/ ux0:/data/retroarch/system/bios_CD_U